Polycarboxy acid esters of certain oxypropylated amines



Patented May 25, 1954 2,679,510 POLYCARBOXY ACID ESTERS OF CERTAINOXYPROPYLATED AMINES Melvin De Groote, University City, Mo., assignor toPetrolite Corporation, a corporation of Dela- Ware No Drawing.Application May 14, 1951, Serial No. 226,303

7 Claims.

The present invention is concerned with certain new chemical products,compounds, or comsolving emulsions of the water-in-oil type, andparticularly petroleum emulsions. See my copending application, SerialNo. 226,302, filed 14, 1951, now Patent No. 2,526,914.

containing diol obtained by the oxypropylation of methyl diethanolamine.Furthermore, the dihydroxylated compound prior to esterification must beWater-insoluble and kerosene-soluble.

l Hooc '11b onfioonornczlrrczmo(ogmow mooomfl' CH3 in which n and n areWhole numbers with the proviso that n plus 11, equals a sum varying from15 to 80; n is a whole number not over 2 and R is the radical of thepolycarboxy acid /COOH and preferably free from any radicals having morethan 8 uninterrupted carbon atoms in a single group, and with thefurther proviso that the parent dihydroxy compound prior toesterification be Water-insoluble and kerosene-soluble.

Attention is directed to the co-pending application of C. M. Blair, Jr.,Serial No. 70,811, filed January 13, 1949, now Patent No. 2,562,878, inwhich there is described, among other things, a process for breakingpetroleum emulsions of the Similarly, there have been used esters ofdicarboxy acids and polypropylene glycols in which 2 moles of thedicarboxy acid ester have been reacted with one mole of a polypropyleneglycol having a molecular Weight, for example, of 2,000 so as to form anacidic fractional ester. Subsequent examination of what is said hereinin comparison with the previous examples as well as the hereto appendedclaims will show the line of delineation between such somewhatcomparable compounds. Of greater significance, however, is what is saidsubsequently in regard to the structure of the parent diol as comparedto polypropylene glycols whose molecular weights may vary from 1,000 to2,000.

Although the herein described products have a number of industrialapplications, they are of particular value for resolving petroleumemulsions of the water-in-oil type that are commonly referred as cutoil, roily oil, emulsified oil, etc., and which comprise fine dropletsof naturally-occurring waters or brines. dispersed in a more or lesspermanent state throughout the oil which constitutes the continuousphase of the emulsion. This specific application is described andclaimed in my co-pending application, Serial No. 226,302, filed May 14,1951.

The new products are useful as wetting, detergent and leveling agents inthe laundry, textile age, coal washing waste water, and various tradewastes and the like; as germicides, insecticides, emulsifying agents,as, for example, for cosmetics, spray oils, water-repellent textilefinishes; as lubricants, etc.

For convenience, what is said hereinafter will be divided into fourparts:

Part 1 is concerned with the preparation of the oxypropylationderivative of methyl diethanolamine;

Part 2 is concerned with the preparation of the esters from theoxypropylated derivatives;

Part 3 is concerned with the structure of the oxypropylation productsobtained from the specified tertiary amine. Insofar that such materialsare dihydroxylated there is a relationship particular part; and

Part 4 is concerned with certain derivatives which can be obtained fromthe oxypropylated methyl diethanolamine. In some instances suchderivatives are obtained by modest oxyethylatio-n preceding theoxypropylation step, or oxypropylation followed'by oxyethylation. diolshaving somewhat difierent properties which can then be reacted with thesame polycarboxy acids or anhydrides described in Part 3 to giveeifective demulsifying agents. For this reason a description of theapparatus makes; casual pressure during reaction, etc.

, per square inch.

mention of oxyethylation. For the same reason there is brief mention ofthe use of glycide.

PART 1 becomes obvious that it is adapted for oxyethyla tion as well asoxypropylation.

Oxypropylations are conducted under a wide variety of conditions, notonly in regard to presence or absence of catalyst, and the kind ofcatalyst, but also in regard to the time of reaction, temperature ofreaction, speed of reaction, For instance, oxyalkylations can beconducted at temperatures up to approximately 200 C. with pressures inabout the same range up to about 200 pounds They can be conducted alsoat temperatures approximating the boiling point of water or slightlyabove, as for example 95 to I C. Under such circumstances the pressurewill be less than pounds per square inch unless some special procedureis employed as is sometimes the case, to wit, keeping an atmosphere ofinert gas such as nitrogen in the vessel during the reaction. Such lowtemperature-low reaction ,rate oxypropylations have been described verycompletely in U. S. Patent No. 2,448,664, to H. R. Fife et al, datedSeptember 7, 1948. Low temperature, low pressure oxypropylations areparticularly desirable where the compound being subjected tooxypropylation contains one, two or three points of reaction only, suchas monohydric alcohols, glycols and triols.

Although the word glycol or diol? isusually ,applied to compoundscontaining carbon, hydrogen, and oxygen only, yet thenitrogen-containing compounds hereinare diols in the sense that they aredihydroxylated. Thus, the conditions ,which apply. to the oxypropylationof certain glycols also apply in this instance.

Since low pressure-low temperature-low reaction speed oxypropylationsrequire considerable time, for instance, 1 to '7 days of 24 hours each Ito complete the reaction they are-conducted as a rulewhether on alaboratory scale, pilot plant scale, or large scale, so as tooperateautomatically. The prior figure of sevendays applies especiallyto large-scale operations. 'I have used conventional equipment with twoadded automatic features; (a) a solenoid controlled valve which shuts01f the propylene oxide in event that Q the temperature gets outside apredetermined and set range, for instance, 95 to 120 C., and. (b)another solenoid valve which shuts off the propylene oxide (or for thatmatter ethylene oxide if it is being used) if the pressure gets beyond apredetermined range, such as 25 to pounds. Otherwise, the equipment issubstantially the same as is commonly employed for this purpose wherethe pressure of reaction is higher, speed of reaction is higher, andtime of reaction is much shorter. In such instances such automaticcontrols are not necessarily used.

Thus, in preparing the various examples I have found it particularlyadvantageous to use laboratory equipment or pilot plant which, isdesigned to permit continuous oxyalkylation whether it be oxypropylationor oxyethylation. With certain obvious changes the equipment can be usedalso to permit oxyalkylation involving the use of glycide where nopressure is involved except the vapor pressure of a solvent, if any,which may have been used as a diluen As previously pointed out themethod of using propylene oxide is the same as ethylene oxide. Thispoint is emphasized only for the reason that the apparatus is sodesigned and constructed as to use either oxide.

The oxypropylation procedure employed in the preparation of theoxyalkylated derivatives has been uniformly the same, particularly inlight of the fact that a continuous automatically-controlled procedurewas employed. In this procedure the autoclave was a conventionalautoclave made of stainless steel and having a capacity of approximately15 gallons and a working pressure of one thousands pounds gaugepressure. This pressure obviously is far beyond any requirement as faras propylene oxide goes unless there is a reaction of explosive violenceinvolved due to accident. The autoclave was equipped with theconventional devices and openings, such as the variable-speed stirreroperating at speeds from R. P. M. to 500 R. P. M.; thermometer well andthermocouple for mechanical thermometer; emptying outlet; pressuregauge, manual vent line; charge hole for initial reactants; at least oneconnection for introducing the alkylene oxide, such as propylene oxideor ethylene oxide, to the bottom of the autoclave; along with suitabledevices for both cooling and heating the autoclave, such as a coolingjacket, and, preferably, coils in addition thereto, with the jacket soarranged that it is suitable for heating with steam or cooling withwater and further equipped with electrical heating devices. Suchautoclaves are, of course, in essence small-scale replicas of the usualconventional autoclave used in oxyalkylation procedures. In someinstances in exploratory preparations an autoclave having a smallercapacity, for instance, approximately 3 /2 liters in one case and about1% gallons in another case, was used.

Continuous operation, or substantially continuous operation, wasachieved by the use of a separate container to hold the alkylene oxidebeing employed, particularly propylene oxide. In conjunction with thesmaller autoclaves, the container consists-essentially of alaboratorybomb having a capacity of about one-half gallon, orsomewhatinexcess thereof. In some instances a larger bomb was used, towit, one having a capacity of about one gallon. This bomb was equipped,also, with an inlet for charging, and an eductor tube going to thebottom of the container so as to permit discharging of alkylene oxide inthe liquid phase to the autoclave. A bomb having a capacity of aboutpounds was used in connection with the l5-gallon autoclave. Otherconventionalequipment consists, of course, of the rupture disc, pressuregauge, sight feed glass, thermometer connection for nitrogen forpressuring bomb, etc. The bomb was placed on a scale during use. Theconnections between the bomb and the autoclave. were flexible stainlesssteel hose or tubing so that continuous weighings could be made withoutbreaking or making-any 'connections. This-applies also to the nitrogenWhich provided such as safety Attention is mined range or pressure inthe autoclave passes out of predetermined range.

With this particular arrangement practically all oxypropylations becomeuniform in that the reaction temperature was held within a few degreesof any selected point, for instance, if 105 C. was selected as theoperating temperature the maximum point would be at the most 110 C. or112 C., and the lower point would be 95 or possibly 98 C. Similarly, thepressure was held at approximately 30 pounds maximum within a poundvariation one way or the other, but might drop to practically zero,especially where no solvent such as xylene is employed. The speed ofreaction was comparatively slow under such conditions as compared withoxyalkylations at 200 C. Numerous reactions were conducted in which thetime varied from one day (24 hours) up to three days (72 hours), forcompletion of the final member of a series. In some instances thereaction may take place in considerably less time, i. e., 24 hours orless, as far as a partial oxypropylation is concerned. The minimum timerecorded was about a 3-hour period in a single step. Reactions indicatedas being complete in hours may have been complete in a lesser actionswere complete in a shorter period of time, for instance, 4- to 5 hours.'In the addition of propylene oxide, in the autoclave equipment as faras possible the valves were set so all the propylene oxide if fedcontinuously would be added at a rate so that the predetermined amountwould react within the first hours of the 24-hour period or two-thirdsof any shorter period. This meant that if the reaction was interruptedautomatically for a period of time for pressure to drop or temperatureto drop the predetermined amount of oxide would still be added in mostinstances well within the predetermined time period. Sometimes where theaddition was a comparatively small amount in a 10-hour period therewould be an unquestionable speeding up of the reaction, by simplyrepeating the examples and using 3, 4 or 5 hours instead of 10 hours.

When operating at a comparatively high temperature, for instance,between 150 to 200 C., an unreacted alkylene oxide such as propyleneoxide, makes its presence felt in the increase in pressure or theconsistency of a highe pressure. However, at a low enough temperature itmay happen that the propylene oxide goes in as a liquid. If so, and ifit remains unreacted there is, of course, an inherent danger andappropriate steps must be taken to safeguard against this possibility;if need be a sample must be with-- drawn and examined for unreactedpropylene oxide. One obvious procedure, of course, is to oxypropylate ata modestly higher temperature, for instance, at 140 to 150 C. Unreactedoxide affects determination of the acetyl or hydroxyl value of thehydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards thelatter stages of reaction, the longer the time required to add a givenamount of oxide. One possible explanation is that the molecule, beinglarger, the opportunity for random reaction is decreased. Inversely, the

lower the molecular weight the faster the reaction takes place. For thisreason, sometimes at least, increasing the concentration of the catalystdoes not appreciably speed up the reaction, particuwhen the productsubjected to oxyalkylaa comparatively high molecular weight.

or ten days time may lapse to obtain some of the higher molecular weightderivatives from monohydric or dihydric materials.

In a number of operations the counterbalance scale or dial scale holdingthe propylene oxide bomb was so set that when the predetermined amountof propylene oxide had reaction the scale movement through a timeoperating device was set for either so that reaction continued for 1 thefinal addition of the last propylene oxide and thereafter the operationwas shut down. This particular device is particularly suitable for useon larger equipment than laboratory size autoclaves, to wit, onsemi-pilot plant or pilot plant size, as well as on large scale size.This final stirring period is intended to avoid the presence ofunreacted oxide.

In this sort of operation, of course, the temperature range wascontrolled automatically by either use of cooling water, steam, orelectrical heat, so as to raise or lower the temperature. The pressuringof the propylene oxide into the reaction vessel was also automaticinsofar that the feed streams were set for a slow continuous run whichwas shut off in case the pressure passed a predetermined point aspreviously set out, All the pointsof design, construction, etc., wereconventional including the gauges, check valves and entire equipment. Asfar as I am aware at least two firms, and possibly three, specialize inautoclave equipment such as I have employed in the laboratory, and areprepared to furnish equipment of this same kind. Similarly pilot plantequipment is available. This point is simply made as a precaution in thedirection of safety. Oxyalkylations, particularly involving ethyleneoxide, glycide, propylene oxide, etc., should not be conducted except inequipment specifically designed for the purpose.

Example 1a The starting material was a commercial grade of methyldiethanolamine as supplied by Carbide & Carbon Chemicals Corporation,New York city, N. Y. Since this material is definitely basic the initialoxypropylation did not require the ada capacity gallons or so, or on theaverage of about 10 pounds of reaction mass. The speed of the stirrercould be varied from to 350R. P. M. 3.94 pounds of methyl diethanolaminewere charged into theautoclave. The reaction pot was flushed out withnitrogen. The autoclave was sealed and the automatic devices adjustedfor injecting 6.31 pounds of propylene oxide in an hour. This timeperiod had no particular significance in this instance for the reasonthat the reactant, being strongly basic, absorbed or reacted withpropylene oxide practically as fast as it was added. The entireprocedure required only about ten minutes. Similarly, the pressureregulator was set for a maximum of 32 pounds per square inch. Since thepropylene oxide reacted with the aminerpractically. as rapidly as:added, there was no pressure. The initial introduction of the propyleneoxide was not started until the heating deviceshad raised the.temperature to about the boiling point of :water. As previously pointedout, the reactionwas complete in a substantially short period' Thereactants were too small in quantity to .serve satisfactorily in alarger autoclave. However, at the end of this reaction whentheoxypropylated productrepresented approximately 10 pounds, therewas nodifiiculty in the use of ourlarger autoclave and, thus the entirereaction mass was transferred to a larger autoclave, one having a-gallon capacity, or approximately 120 pounds of reaction mass. Thislarge autoclave was employed in all subsequent examples, to wit,Examples 2a through 6a.

Example 2a Example 5a Approximately 68.94 pounds of the reactionmass-identified as Example 4a, preceding, and equivalent to 1.58 poundsof amine, 66.96 pounds of oxide and .4 pound of caustic soda, weresubjected to further oxypropylation in the same manner as describedinExamples 2a and 3a, preced- As previously noted-the entire reactionmass, The time period 2 E same, to 3f identified as Example 1a precedingwas trans hours. The amount or oxide added was 347a pounds. It was addedat the rate of about 10 ferred to a larger autoclave. This reaction massrepresented 3.94 pounds of the amine and 6.31 pounds of propylene oxide.To this reaction mass there was added one pound of caustic soda. Thisreaction mass was oxypropylated with 43.75 pounds of propylene oxide.The oxypropylation was conducted in such a manner that the pressuregauge was set for 35 to 37 pounds maximum pressure and the temperaturewas set for 220 to 225 F. (moderately above the boiling point of water).Actually the bulk of the reaction could take place and probably did takeplace at a lower temperature. The time involved was a 3-hour period. Theoxide was added at a rate of about 20 pounds per hour, and thus therewas a period at the end of the 3-hour time interval which representedmerely stirring without addition of oxide. When the reaction wascomplete part of the mass was withdrawn and the remainder subjected tofurther oxypropylation as described in Example 3a, immediatelyfollowing.

Example 30.

47 pounds of the reaction mass previously identified as Example2a,preceding, and equivalent to 3.37 pounds of the amine, 42.78 pounds ofpropounds per hour. At the end of the reaction period part of the samplewas withdrawn and the remainder of the reaction mass was subjected againto further oxypropylation as described in Example 6a; following.

Example 6a Approximately 69.19 pounds of the reaction mass, equivalentto 1.06 pounds of the amine, 67.86 pounds of the oxide, and .27 pound ofcaustic soda were subjected to further oxypropylation under the sameconditions as described in the example immediately preceding. Thereaction time was somewhat longer, to wit, 5 hours. The amount of oxideadded was comparatively small, to wit, 15.75 pounds. It was added at therate of 4 pounds per hour.

In this particularvseries ofexamples the oxypropylations were stopped atthis stage. In other series I have continued the oxypropylation so thetheoretical molecular weight varied from 12,000 to 15,000but theincrease in molecular weight by hydroxyl determination was comparativelysmall, varying from 4300 to approximately 4975.

TABLE 1 Composition Before Composition at End i) W M g Ex. y ax res TimeNo. Amine Oxide Cata- Theo. Amine Oxide Gataggg 2 lbs H Amt, Amt, 1yM01. Amt, Amt lyst, mm lbs. lbs. lbs. Wt. lbs. lbs

1a 3, 94 3. 94 0. 30 220-225 21L 3. 94 G. 31 1. 0 1, 630 3. 94 50. 00 1.0 890 220-225 35-37 3 3m 3. 37 42. 78 85 -2, 580 3. 37 81. 28 85 1, 426220-225 35-37 4 4a 2. 34 57. 32 59 5, 370 2. 34 98. 82 2, 060 220-22535-37 4 5a l. 53 66. 90 40 7, 770 1. 58 10K. 71 40 3, 040 220-225 35-374 61L 1. 00 07. $0 27 9, 500 1. 00 83. 61 .27 3, 040 220-225 35-37 5Example 4a 60.25 pounds of the reaction masspreviously identified asExample 3a, and equivalent to 2.34 pounds of the amine, 57

.32 pounds of propylene 7 0 Example 2a was soluble in water, dispersiblein xylene, and insoluble in kerosene; Example 3a was emulsifiable inwater, soluble in xylene, and insoluble in kerosene; Examples 4a, 5a,and 6a.

.were'all insoluble in water, soluble in xylene, and soluble inkerosene. This was true, also, in regard to those products previouslyreferred to which were of a higher molecular weight.

The final product, i. e., at the end of the oxypropylation step, was apale to dark amber fluid with a mere suggestion of a reddish tint. Thiswas more or less characteristic of all the various oxypropylationproducts in the various stages. 'These'products were-of course, slightlyalkaline due to the residual caustic soda and also due to 5 the basicnitrogen atom. The residual basicity due to the catalyst, of course,would be the same if sodium methylate had been used.

Speaking of insolubility in water or solubility in kerosene suchsolubility test can be made simply by shaking small amounts of thematerials in a test tube with water, for instance, using 1% to 5%approximately based on the amount of water present.

Needless to say, there is no complete conversion of propylene oxide intothe desired hydroxylated compounds. This is indicated by the fact thatthe theoretical molecular weight based on a statistical average isgreater than the molecular weight calculated by usual methods on basisof acetyl or hydroxyl value. Actually, there is no completelysatisfactory method for determining molecular Weights of these types ofcompounds with a high degree of accuracy when the molecular weightsexceed 2,000. In some instances the acetyl value or hydroxyl valueserves as satisfactorily as an index to the molecular Weight as anyother procedure, subject to the above limitations, and especially in thehigher molecular weight range. If any difficulty is encountered in themanufacture of the esters as described in Part 2 of the stoichiometricalamount of acid or acid compound should be. taken which corresponds tothe indicated acetyl or hydroxyl value. This matter has been discussedin the literature and is a matter of common knowledge and requires nofurther elaboration. In fact, it is illustrated by some of the examplesappearing in the patent previously mentioned.

PART 2 As previously pointed out the present invention is concerned withacidic esters obtained from the oxypropylated derivatives described inPart 1, immediately preceding, and polycarboxy acids, particularlytricarboxy acids like citric and dicarboxy acids such as adipic acid,phthalic acid, or anhydride, succinic acid, diglycollic acid, sebacicacid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconicacid or anhydride, maleic acid or anhydride adducts as obtained by theDiels-Alder reaction from products such as maleic anhydride, andcyclopentadiene. Such acids should be heat stable so they are notdecomposed during esterification. They may contain as many as 36 carbonatoms as, for example, the acids obtained by dimerization of unsaturatedfatty acids, unsaturated monocarboxy fatty acids, or unsaturatedmonocarboxy acids having 18 carbon atoms. Reference to the acid in thehereto appended claims obviously includes the anhydrides or any otherobvious equivalents. My preference, however, is to use polycarboxy acidshaving not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) frompolycarboxy acids and glycols or other hydroxylated compounds is wellknown. Needless to say, various compounds may be used such as the lowmolal ester, the anhydride, the acyl chloride, etc. However, for purposeof economy it is customary to use either the acid or the anhydride. Aconventional procedure is employed. On a laboratory scale one can employa resin pot of the kind described in U. S. Patent No. 2,499,370, datedMarch '7, 1950, to De Groote and Keiser, and particularly with one moreopening to permit the use of a porous spreader if hydrochloric acid gasis to be used as a catalyst. Such device or absorption spreader consistsof minute alundum thimbles which are connected to a glass tube. One canadd a sulfonic acid such as para-toluene sulfonic acid as a catalyst.because in some perature is too high. In the case of polycarboxy acidssuch as diglycollic acid, which is strongly acidic there 15 no need toadd any catalyst. The use of hydrochloric acid gas has one advantageover paratoluene sulfonic acid and that is that at the end of thereaction it can be removed by flushing out with nitrogen, whereas thereis no reasonably convenient means available of removing the paratoluenesulfonic acid or other sulfonic acid employed. If hydrochloric acid isemployed one need only pass the gas through at an exceedso as to keepthe reaction mass acidic. Only a trace of acid need be present. I haveemployed hydrochloric acid gas or the aqueous acid itself to eliminatethe initial basic material. My preference, however, is to use nocatalyst whatsoever.

The products obtained in Part 1 preceding may contain a basic catalyst.As a general procedure I have added an amount of half-concentratedhydrochloric acid considerably in excess neutralize the residual shakenthoroughly and It is then filtered present until the phase-separating ofwhat is required to catalyst. The mixture is allowed to stand overnight.

and refluxed with the xylene water can be separated in a trap. As soonas the product is substantially free from water the distillation stops.This preliminary step can be carried out in the flask to be used foresterification. If there is any further deposition of sodium chlorideduring the reflux stage needless to say a second filtration may berequired. In any event the neutral orslightly acidic solution of theoxypropylated derivatives described in Part 1 is then diluted furtherwith as previously described, such as phthalic anhydride, succinic acidor anhydride, diglycollic acid, etc. The

can then add a small amount of anhydrous sodium sulfate (suflicient inquantity to take up any water that is present) and then subject the massto centrifugal force so as to eliminate the hydrated sodium sulfate andprobably the sodium chloride formed. The clear, somewhat viscous dark topale amber liquid so obtained may contain a small amount of sodiumsulfate or sodium chloride but, in any event, is perfectly acceptablefor esterification in the manner described.

It is to bepointed out that the-products here I described are notpolyesters in the sensethat there is a plurality of both diol radicalsand acid radicals; the product is characterized by havin only one diolradical.

In some instances and, in fact, in many instances I have found that inspite of the dehydration methods employed above that a mere traceofwater still comes through and that this mere trace of water certainlyinterferes with the acetyl or hydroxyl value determination, at leastwhen a number of conventional procedures'are used and may retardesterification, particularly where there is nosulfonic acid orhydrochloric 1 acid present as a catalyst. Therefore, I have preferredto use the following procedure: I have employed about 200 grams-of thediol as describedin Part 1, preceding; I have added about 60 grams ofbenzene, and then refluxed this mixture in the glass resin pot using aphase-separating trapiuntil the benzene carried out all thewater presentas water of solution or the equivalent. Ordinarily this refluxingtemperatureis apt to be in the neighborhood of 130 to possibly 150 C.When all this water or moisture has been removed I also withdrawapproximately grams or a little lessbenzene and then add. the requiredamount of the carboxy reactant-and also about 150 gramsof a high boilingaromatic petroleum solvent. These solvents are sold by various oilrefineries and, as far assolvent effect act as if they were almostcompletely aromatic incharacter; Typical distillation data in theparticular type I have em-' ployed and found very satisfactory are thefollowing:

0 main. If the solvent 12 :2 is added, refluxing is conat "ahigh'temperature,

After this-material tinued, and, of course, .is to wit,.about-160-to 170C. If the carboxy reactant is ananhydride needlessto say no water ofreaction'appears; if the carboxy reactant is an acid, water of reactionshould appear and should be eliminatedat the above reaction temperature.If it is not eliminated I simply separate out another 10 or- 20 .cc.;ofbenzene by means of the phase-separating trap and thus raise thetemperature to 180 or 190 C., or even to 200 C., if need'be. Mypreference is not to go above 200 C.

The :use of such solvent is extremely satisfactory :providedone'does-not attempt to remove the solvent-subsequently except by vacuumdistillation and provided there is no objection to a little residue;Actually, when these materials are used for. a purposesuch asdemulsification the solvent might just as Well as be allowed to reis tobe removed by distillation; and particularly vacuum distillation, thenthe .high boiling aromatic petroleum solvent might-wellbezreplaced bysome more expensive solvent; such' as'decalin or an alkylated decalinwhich-haste rather definite or close range boiling point. The removal ofthe solvent, of course, is purely a conventional procedure and requiresnoelaboration.

lathe-appended table Solvent #7-3, which appearsin allinstances; is amixture of 7 volumes of the.aromaticpetroleum, solvent previouslydescribcdiand 3 volumes of benzene; This was used, or a similar mixture,inthe manner previously described. In a large number of similar examplesdecalinv has .been used but it is my preference to use the. abovementioned mixture and particu- I. B. P. 142 C. ml. 24 5 m1 0 55, 2,, glarly. w1th..the preliminary step of removing all 10 'i 248 the water...If onedoes not intend-to remove the 15 215 252 solvent my-preference isto use the petroleum m o m o p 49 solventrbenzene mixture althoughobviously any 20 Q m -v- 252 of the othermixtures, such as decalin andxylene, 25 ml., 220 C. ml.,.260 C. can be employed 0 11 5 C-Thedataincluded in the subsequent tables, 35 ml., 230 C. ml., 270 C. i.e., Tables2 and.3, are self-explanatory, and 40 ml., 234 .C.. ml., 280C. 4 very complete and. it is believedno further ela- 45 ml., 237 C,ml., 307 C. boration is necessary:

TABLE 2 a Mol Theo. Amt. of EX..NO. Theo Actual Wt. Amtci v EX: NO" ofM. W Hy- Hy- Based Hyd. P91": ogAcid on of dniixyl droxyl on CmpdPolycarboxy Redctent gaihoxy ster 011666111.

Ompd. H. 0. ME. Value rift? (g (gm) 16 26 1,636 68.9 126 896 200Diglycolic Acid 59.6 26 26 1,630 68.9 126. 896 198 Phthalic Anh dridc...65.5 36 26 1,636 68.9 126 896 198 M81616 Anh di-idc.... 43.2 46 26 1,63068.9 126 866 198 Citraconic Anhydridc. 40.5 56 26 1,630 68.9 126 896 199Aconitic Acid 66 26 1,636 68.9. 126 896 198 Oralic Acid 556 7b 311 2,58043.5 78.8 1,426 202 Diglycolic Acid 38,0 86 36 2,580 43.5 78.8 1,426 262Phthalic Anhydridc... 42.6 90 36 2,580 43.5 78.8 1,426 203 MalcicAnhydridc-.. 27.8 106 36 2,580 43.5 78.8 1,426 202 Citraconic Anhydridc.31.8 116 36 2,580 43.5 78.8. 1,426 263 Acciiiiic Acid. 494 126 36 2,58643.5 78.8 1,426 263 Oxalic Acid... 35.8 136 46 5,376 26.9 54.5 2,666 263D iycclicAci .".4 146 46 5,370 26.9 54.5 2,666 208 P11666116Anhydride... 36.6 156 46 5,376 26.9 54.5 2,666 268 MaleicAnhydr1de 19.9166 46 5,376 26.9 54.5 2,666 268 oiiracciiic Anhydride. 22.6 176 465,376 26.9 54.5 2,666 268 Accnmc Acid 35.6 186 46 5,376 26.9 54.5 2,666267 0156110 Acid- 25.4 196 56 7,770 14.4 36.8 3,646 205 DlglycolicAcid.-. 18.0 266 56 7,776 14.4 36.8 3,646 264 Piithaiic Anhydrid 26.6216 56 7, 770 14.4 36.8 3,646 265 6491916 Anhydride 13.2 226 56 7,77614.4 36.8 3,646 203 Citraconic Anhydride. 15.6 236 56 7,776 14.4 36.83,646 264 Aconitic Acid 23.3 246 56 7, 776 144 36.8 3,646 266 OxalicAcid 17.6 256 66 9, 566 11.8 30.8 3,640 267 Diglycolic Acid 15.1 266 669,569 11.8 36.8 3,646 265 Phthalic Anhydridc... 16.7 276 66 9,566 11.880.8 3,646 266 Maleic Anhydridm... 11.1 286 6a 9, 500 11.8 30.8 3, 640209 Citracom'c Anhydride. l2.0 296 66 9,566 11.8 30.8 3,646. 266Aconitic Acid 19.6 30b 66 9,566 11.8 36.8 3,646 265 Oxalic Acid 14.1

Ester- Time of Amt.

Water Ex. N o. of ification Ester- Acid Ester solvent Temp, ificationOut (00.)

C. (hrs) 5g 8.1 IIIIIIII "6ft 5b "5Y6 (it 24.5 71 6.1 8!: 0.6

The procedure for manufacturing the esters has been illustrated bypreceding examples. If for any reason reaction does not take place in amanner that is acceptable, attention should be directed to the followingdetails: (a) Recheck the hydroxyl or acetyl value of the oxypropylatedprimary amines of the kind specified and use a stoichiometricallyequivalent amount of acid; (b) if the reaction does not proceed withreasonable speed either raise the temperature indicated or extend theperiod of time up to 12 or 16 hours if need be; (c) if necessary, use/2% of para toluene sulfonic acid or some other acid as a. catalyst; (d)if the esterification does not produce a clear product a check should bemade to see if an inorganic salt such as sodium chloride or sodiumsulfate is not precipitating out. Such salt should be eliminated, atleast for exploration experimentation, and can be removed by filtering.Everything else being equal, as the size of the molecule increases andthe reactive hydroxyl radical represents a smaller fraction of theentire molecule, more difliculty is involved in obtaining completeesterification.

Even under the most carefully controlled cond ions of oxypropylationinvolving comparative- 1y low temperatures and long time of reactionthere are formed certain compounds whose composition is still ucts cancontribute a substantial proportion of the final cogeneric reactionmixture. Various suggestions have been made as to the nature of thesecompounds, such as being cyclic polymers of propylene oxide, dehydrationap earance of a vinyl radical,

aldehyde, ketone, or allyl alcohol. In some instances an attempt toreact the stoichiometric amount of a polycarboxy acid with theoxypropylated derivative results in an excess of the carboxylatedreactant for the reason that apparent- 1 under conditions of reactionless reactive hydroxyl radicals are present than indicated by thehydroxyl value. Under such circumstances there is simply a residue ofthecarboxylic reactant which can be removed by filtration or, if desired,the esterification procedure can be repeated using obscure. Such sidereaction prodan appropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value and conventional procedureleaves much to be desired due either to the cogeneric materialspreviously referred to, or for that matter, the presence of anyinorganic salts or propylene oxide. Obviously this oxide should beeliminated.

The solvent employed, if any, can be removed from the finished ester bydistillation and particularly vacuum distillation. The final products orliquid what more viscous.

PART 3 Previous reference has been made to the fact that diols(nitrogen-free compounds) such as polypropyleneglycol of approximately2,000 mopounds are different from such diols although it is true, arehigh molecular weight dihydroxylated compounds. instant compounds havepresent a nitrogen atom which is at least modestly basic. In any event,such nitrogen atom, even if of comparative basicity, must in alllikelihood influence the orientation of acidic molecules at interface.

or 20% better on a quantitative basis than the simpler compoundpreviously described, and demulsify faster and give cleaner oil in manyinstances. The method of making such comparative tests has beendescribed in a booklet entitled Treating Oil Field Emulsions, used inthe Vocational Training Course, Petroleum Industry Series, of theAmerican Petroleum Institute.

It may be well to emphasize also the fact that oxypropylation does notproduce a single com pound but a cogeneric mixture. The factor involvedis the same as propylating a monohydrlc alcohol or a Momentarily,polypropylene glycol, such as polypropylene glycol weight. Propyleneglycol has a primary alcohol radical and a secondary alcohol radical. Inthis sense the building unit which forms polypropylene glycols is notsym- Obviously, then, polypropylene glycols can be obtained, at leasttheoretically, in which two secondary alcohol groups are united or asecondary alcohol group is united to a primary course, in each instance.

Usuallyvno effort is madeto .difierentiate be-' tween oxypropylationtaking place, for example, at the primaryalcoholrradical' or thesecondary alcohol :radical.--'Actually, when such products are obtained;such as a high. molal polypropylene glycol or the" products obtained inthe manner herein .--described:one does not obtain a single derivative-such'asI-IO(RO) nH in which 1L has one and'only' one value, forinstance 14, or 16, or the likes Rather, one obtains a cogeneric mixtureof closely related or touchinghomologues. Thesematerialshinvariably havehigh molecular weights and cannot be-separated from one anotherby anyknownprocedure without decomposition; The properties of such mixturerepresent the contribution of the various individual members of'themixture. On a statistical basis, of courseyn can be appropriatelyspecified. For practical -purposes-one need only consider theoxypropylation of a monohydric alcohol because in essence this issubstantially the mechanism involved. Even in such instances where oneis concernedwith a monohydric reactant one cannot draw a single formulaand say that by following such procedure one .can readily obtain 80% or90% or 100% of such compound. However, in the case of at leastmonohydric initial reactants one can readily draw the formulas of alarge number of compounds which appear in some of the probable mixturesor can be prepared as components and mixtures which are manufacturedconventionally.

Simply by way'of illustrating reference is made to the co-pendingapplication of De Groote, Wirtel and Pettingill, Serial No. 109,791,filed August 11, 1949, now Patent No. 2,549,434.

However, momentarily referring again to a monohydric initial reactant itis obvious that if one selects any such simple hydroxylated compound andsubjects such'compound to oxyalkylation, such as oxyethylation, oroxypropylation, it becomes obvious that one is really producing apolymer of the alkylene oxides except for the terminal group. This isparticularly true where the amount of oxide added is comparativelylarge, for instance, 10, 20, 30, 40, or 50 units. If such compound issubjected to oxyethylation so as to introduce 30 units of ethyleneoxide, it is well known that one does not obtain a single constitutentwhich, for the sake of convenience, may be indicated as RO(C2H4O)$0OH.Instead, one obtains a cogeneric mixture of closely related homologues,in which the formula may be shown as the following, RO(C2H4O)1LH,wherein n, as far as the statistical average goes, is 30, but theindividual members present in significant amount may vary from instanceswhere n has a value of 25, and perhaps less, to a point where n mayrepresent 35 or more. Such mixture is, as stated, a cogeneric closelyrelated series of touching homologous compounds. Considerableinvestigation has been made in regard to the distribution curves forlinear polymers. Attention is directed to the article entitledFundamental principles of condensation polymerization, by Flory, whichappeared in Chemical Reviews, volume 39, No. 1, page 13'].

Unfortunately, as has been pointed out by Flory and other investigators,there is no satisfactory method, based on e'ther proportion of thevarious members of touching homologous series which appear in cogenericcondensation products of the kind described. This means that from thepractical standpoint, i. e., the ability to describe how to make theproduct under consideration and how to repeat such production time aftertime without difficulty, it is necessary to resort to some other methodof description, or'else consider the value of n, in formulas such asthose which have appeared previously and which appear in the claims, asrepresenting both individual constituents in which n has a singledefinite value, and also with the understanding that n represents theaverage statistical value based on the assumption of completeness ofreaction.

This may be illustrated as follows: Assume that in any particularexample the molal ratio of the propylene oxide to the present or otherspecified amine is 15 to 1. Actually, one obtains products in which nprobably varies from 10 to 20, perhaps even further. The average value,however, is assuming, as previously stated, that the reaction iscomplete. The product described by the formula is best described also interms of method of manufacture.

PART 4 Previous reference has been made to other oxyalkylating agentsother than propylene oxide, such as ethylene oxide. Obviously variantscan be prepared which do not depart from what is said herein butdoproduce modifications. The present methyl. diethanolamine can be reactedwith ethylene oxide in modest amounts and then subjected tooxypropylation. provided that the resultant derivative is(alwater-insoluble, (b) kerosene-soluble, and (c) has present 15 to 80alkylene oxide radicals. Needless to say, in order to havewater-insolubility and kerosene-solubility the large majority must-bepropylene oxide. Other variants suggest themselves as, for example,replacing propylene oxide by butylene oxide.

More specifically, one mole of the amine can be treated with 2, 4 or 6moles of ethylene oxide and thentreated with propylene oxide so as toproduce a water-insoluble, kerosene-soluble oxyalkylated amine in whichthere are present 15 to oxide radicals as previously specified.Similarly thepropyleneoxide can be added first and then the ethyleneoxide, or random oxyalkylation can be employed using a mixture of thetwo oxideswThe compounds so obtained are readily esterified in'the samemanner as described in Part 2, preceding. Incidentally, the diolsdescribed in Part 1 or the modifications described thereincan be treatedwithvarious reactants such as glycide, epichlorohydrin, dimethylsulfate, sulfuric acid, maleic anhydride, ethylene imine, etc.- Iftreated with epichlorohydrin or monochloracetic acid the resultantproduct can be further reacted with a tertiary amine such as pyridine,or the like, to give quaternary ammonium compounds. If treatedwithmaleic anhydridev to give a total ester the resultant can be treatedwith sodium bisulfite to yield a sulfosuccinate. A sulfo group can beintroduced also by means of a sulfating agent as-previously suggested,or by treating the chloroacetic acid resultant with sodium sulfite.

I have found that if such hydroxylated compound or compounds are reactedfurther so as to produce entirely new derivatives, such new derivativeshave the properties of the original hydroxylated compound insofar thatthey are effective and valuable demulsifying agents for resolution ofwater-in-oil emulsions as found in the petroleum industry, as breakinducers in doctor treatment of sour crude, etc.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

l. Hydrophile synthetic products; said hydrophile synthetic productsbeing characterized by the following formula:

I I ll CHa in which n and n are whole numbers with the proviso that nplus 12' equals a sum varying from 15 to 80; n" is a whole number notover 2 and R is the radical of a polycarboxy acid COOH 18 in which n andn are whole numbers with the proviso that n plus 12 equals a sum varyingfrom 15 to 80; and R is the radical of a dicarboxy acid COOH saiddicarboxy acid having not more than 8 carbon atoms.

3. The product of claim 2 wherein the dicarboxy acid is phthalic acid.

4. The product of claim 2 wherein the dicarboxy acid is maleic acid.

5. The product of claim 2 wherein the dicarboxy acid is succinic acid.

6. The product of claim 2 wherein the dicarboxy acid is citraconic acid.

7. The product of claim 2 wherein the dicarboxy acid is diglycollicacid.

No references cited.

1. HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTSBEING CHARACTERIZED BY THE FOLLOWING FORMULA: